What a wonderful and unique space! I’m not sure what I see in that narrow curved space on the patio where that transitions to the seating area. It looks like a low divider of some sort? I think that entire arc might be a good spot for a ground cover that tolerates foot traffic… creeping red thyme or Corsican mint or along those lines. Just one type all the way along that curve. It will create a tidy band of color emphasizing that transition. Maybe it’d work at the base of the stone wall, too. A garden center may be a helpful resource for a few small plants to tuck into crevasses on the rock wall.

I might rework the plantings under the lovely tree, with fewer plant types or colors (or even just one or two), so it feels a bit more cohesive.

I’m just a hobby gardener but these came to mind while looking at you photos. What a fun project!

I would not clutter the stonework with planters or boxes. Imo they look tacky and too modern. I'd get rid of the brown boxes which are not in keeping with the native stonework. You have a fabulous magnolia which is already suitably underplanted. The space is interesting, well weathered and has lots of plantings already. I'd concentrate on the beds, not containers. You don't need to fill every space. I would leave well alone and avoid clutter.

Maybe have an all weather rattan suite by the patio doors if that gets the sun. So far none of the furniture looks very comfortable. And bear in mind there will only be about three days a year when it's nice enough to spend any time sitting outside.😉

Does the hedge mark your back boundry? Is some of it dead? I would want a small tree or two to screen out the huge gray buildings.

Here are a few suggestions:

Instead of the low planters, I'd invest in a few tall, bold, heavy pots to place in strategic spots on the patio -- maybe by the main doorway, by a transition point, and/or where you want to draw the eye to a distant view. You can have dwarf conifers or colorful annual flowers in the pots -- whatever suits your style. Such a gorgeous patio and home!

Thanks for all the advice! ❤️

Your walls are a fabulous feature - You could have a look at Cockermouth Castle for some ideas using walling in garden work. And yep, maybe not put teeny containers and furniture everywhere - You garden has a really fantastic austere beauty - use the open space and landscape, grow some more gnarly specimen trees and keep it stark and disciplined - just soften the edges a bit with campanulas centranthus, aubrieta, mignonette and erigeron...stone and sky can do most of the work.